I could use some help here. I just changed the spark plugs in my 1994 Mercedes Benz E320. W124.

After putting the new ones in (autolite resistor replacing other resistor plugs), and securing everything, I started the car and had a very bad misfire. I went back in and changed the spark plugs back to the ones I took out, and still the misfire.

I picked up a new set of Bosch plug wires and boots for all six cylinders. Also, got another set of new plugs (NGK Platinums.) No difference.

I unplugged and re-plugged the two connectors associated with the intake ductwork several times to assure a good connection.

The car was running fine before I did the spark plug change. What in the world did I do? Can anyone make some educated guesses?

Mark